In the perfumery art there is a continuous interest in new fragrance materials, on the one hand caused by a continuous need for compounds with a new odour character and on the other hand caused by the fact that many of the long Known materials have come under scrutiny lately because of certain undesirable properties. Thus, some well known fragrance materials have been criticized because of their potential instability in some applications. Some of these are well known floral fragrances, such as .alpha.-hexylcinnamaldehyde, 2-methyl-3-(p-tert-butylphenyl)propanal, 2-methyl-3-(p-isopropylphenyl)propanal, 3-(p-tert-butylphenyl)propanal and hydroxycitronellal.
Some alkyl substituted cyclohexanols are long known in perfumery. Thus, S. Arctander, Perfume and Flavor Chemicals mentions: 4-isopropyl-, 4-tert.butyl-, 4-tert.amyl-, 4-heptyl-, 4-ethyl- and 2-methyl-4-tert.amyl-cyclohexanol (monograph no's 2692, 433, 165, 1531, 1201 and 1749). The odour character of all five compounds is overridingly woody with camphoraceous, piney, vetiver and cedar notes, and often also dry with tarry or leathery odour notes. 2-Tert.butylcyclohexanol (monogr.no. 432) is also described as dry woody, camphoraceous and tarry.
Certain 4-isoamylcyclohexanols, particularly di-, tri- and tetra-methyl substituted ones are disclosed in U.S. Pat. No. 4,400,545 as fragrance materials with baisamic, woody, sweet, rooty, musty, earthy and leathery odours.
4-(C8-Alkyl)-cyclohexanols are disclosed in EP 0 005 196 as having an odour resembling that of 4-tert.butyl-cyclohexanol, but less strong. The most important compound is 4-(2,2,3,3tetramethylbutyl)cyclohexanol.
In Japanese patent application JP 02131405 (Hasegawa Koryo Co. Ltd) 2-, 3- and 4-alkylcycloalkanols and esters thereof are described as cockroach repellents. In passing it is stated that these compounds are used as fragrances, but for the alcohols this is not further substantiated than by referring to the Arctander monographs cited above, and no indication of odour character is given in this patent application.
In EP 0 053 979 alkyl substituted 3-(2-alkenyl)cyclopentanols are broadly disclosed with a wide variety of odour notes of the floral, fruity and woody type reminiscent of rose, muguet, bergamot, cucumber, hay-like, dry-woody, cedar or vetiver. The specific compounds shown are all unsubstituted 3-(2-alkenyl)cyclopentanols and 1,2,2-trimethyl-3-(2-alkenyl)cyclopentanols.
In U.S. Pat. No. 4,277,618 1-methyl-2-(C4alkyl)cyclohexanols (C4=sec.butyl or tert.butyl) are disclosed as intermediates in the synthesis of the corresponding acetates. Only the latter are said to be fragrance materials.
In U.S. Pat. No. 3,769,330 1-ethyl-2-(C4-alkyl)cyclohexanols (C4=n.butyl, isobutyl, sec.butyl or tert.butyl) are disclosed as fragrance materials with a woody odour.
It has now been found that 3-alkylcycloalkanols of the formula I below are valuable fragrance materials with strong floral odours with citrus and/or rhubarb and sometimes herbal notes. The floral odour is particularly characterized by its overriding muguet character. The citrus notes are sometimes reminiscent of grapefruit.